Sheet feeding apparatus

ABSTRACT

An apparatus for feeding successive sheets of workstock from a stack or pile thereof and including a sheet storage assembly adapted to operatively support a stack or plurality of sheets of workstock, a delivery assembly for conveying successive sheets of workstock to an associated machine or other operative destination where the workstock sheets are to have some operation performed thereon, and a transfer mechanism for individually transferring successive workstock sheets from the stack thereof to the delivery assembly, the transfer mechanism including at least one vacuum pickup element and means supporting the element for compound movement about rotational and pivotal axes extending transversely of the path of movement of the workstock sheets through the apparatus.

United States Patent Scott [4 1 May 16, 1972 [54] SHEET FEEDING APPARATUS [72] Inventor: Joe Scott, Southfield, Mich.

[73] Assignee: Scott Equipment Company, Inc., Detroit,

Mich.

[22] Filed: Mar. 23, 1970 211 Appl. No.: 21,893

[52] U.S. Cl. ..27l/11,271/28,271/DlG. 1

[58] Field otSearch ..271/28, 27, DIG. 1,11, 12

[56] References Cited UNITED STATES PATENTS 3,185,472 5/1965 Rubow ..271/11 2,085,592 6/1937 Koppe ..271/28 3,252,701 5/1966 Andresen et al.. 271/28 X 3,287,011 11/1966 Currie ..271/28 X 3,460,822 8/1969 Link ..271/26 R Primary Examiner-Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Hamess, Dickey & Pierce [5 7] ABSTRACT An apparatus for feeding successive sheets of workstock from a stack or pile thereof and including a sheet storage assembly adapted to operatively support a stack or plurality of sheets of workstock, a delivery assembly for conveying successive sheets of workstock to an associated machine or other operative destination where the workstock sheets are to have some operation performed thereon, and a transfer mechanism for individually transferring successive workstock sheets from the stack thereof to the delivery assembly, the transfer mechanism including at least one vacuum pickup element and means sup porting the element for compound movement about rotational and pivotal axes extending transversely of the path of movement of the workstock sheets through the apparatus.

54 Claims, 12 Drawing Figures PATENTEDMAY 16 I972 SHEET 1 BF 6 INVENT R J20 J44 Z 4 wr/vz/s:

PATENTEDMAY 16 I972 SHEET 2 BF 6 4/ HL/IW w 4 W 42 42% A, 1

PATENTEDHAY 15 1972 3. 663 009 I SHEET 5 BF 6 SHEET FEEDING APPARATUS BACKGROUND OF THE INVENTION In general, the present invention is directed toward a device for conveying or transferring individual sheets of workstock, such as paper, cardboard, etc., from a suitable source thereof to a delivery conveyor which in turn functions to transfer the sheets to an associated machine or other apparatus adapted to perform an operation thereon, such as printing, cutting, punching or the like. More particularly, the present invention is directed toward a new and improved sheet feeding apparatus which is adapted to operate in a highly efficient manner so as to reduce to the extreme the cycle time required for transferring successive work sheets to an associated machine so that the operational capacity of the machine will be in no way limited by the rate at which the workstock is supplied thereto.

The sheet feeding apparatus of the present invention utilizes a plurality of vacuum pickup elements which are adapted to be selectively communicated with a suitable source of vacuum pressure so that upon engagement thereof with the workstock sheets, the sheets will adhere to the pickup elements, with subsequent movement of the elements toward associated sheet feeding rollers effecting concomitant delivery of the individual sheets of workstock to said rollers. The vacuum pickup elements are operatively supported upon a transfer member which extends transversely of the path of movement of the workstock sheets and which is mounted for rotation, as well as for pivotal movement between workstock engaging and workstock feeding positions, with the result that the pickup elements move along a compound curved path as they transfer the workstock sheets to the delivery assembly. A particular feature of the present invention resides in the fact that the aforesaid transfer member is provided with one or more vacuum pickup assemblies, each of which consists of a plurality of pickup elements, with the elements being movable or rotatable such that as one element is deliveringa workstock sheet to the associated feed rollers, another of the elements is rotating into position to engage and pickup the next successive workstock sheet. Suitable valving means is provided for assuring that the vacuum source is selectively communicated only with the pickup element which is currently serving the sheet pickup function, while clutching and braking means are provided for properly rotationally positioning the pickup elements with the sheets of workstock to be transferred. Additionally, the sheet feeding apparatus of the present invention is provided with means for automatically advancing a stack of workstock sheets so that the next successive sheet to be transferred is always at a preselected position or height with respect to the vacuum pickup elements, as will hereinafter be described in detail.

It has been the practice in similar type sheet feeding apparatus to use a system of cams for effecting movement of the sheet transfer mechanism, with such cams providing an oscillating motion wherein the movement to go down to pickup each sheet is the exact reverse of the movement of the sheet pickup means in an upward direction for delivery to the associated conveyor. The primary disadvantage with this type of arrangement is that the two motions are not entirely compatible. Secondly, because the pickup unit back tracks over the same path, it must hesitate until the trailing edge of the previous sheet has cleared the delivery station and thus in order to achieve a reasonably fast feed rate, such heretofore known units have had to operate inordinately fast. Another problem of heretofore known and used feeding machines has been that the lift units thereof, once they have gripped the sheets, must first lift relatively slowly so that the top sheet separates from the sheets immediately therebelow, then the lift unit must accelerate upwardly and forwardly until it is traveling at nearly the speed of the feed rollers, but as soon as the unit has inserted the sheet, it must come to a very quick stop so that it will not hit the rollers, thus requiring an extremely massive and rugged unit in order to overcome the inertia of movement of the feed mechanism.

In order'to overcome the above problems, the present invention provides an arrangement wherein the lift unit is approximately halfway through its upward stoke at the point where the sheet is stripped from the lift unit. The lift unit continues its upward movement to a preselected limit and then starts downward as the vacuum pickup elements continue to rotate. The pickup elements are arranged and timed to just clear the trailing edge of the prior fed sheet as they are lowered for the next sheet pickup. The vacuum pickup elements continue downward and slowly grip the sheet and then starts to rise. Since the lift motion is crank driven, it is harmonic and allows enough time at the down position to achieve an effective sheet pickup. The primary reason that the present invention is able to operate at an extremely faster rate than heretofore known devices is that it makes more effective use of the timing cycle. In particular, the vacuum pickup elements are disposed in a pickup position at about the same time in the cycle as other feeders are starting down to make a pickup. Thus, at the same feed rate, the present invention can operate at approximately half the speed as would be required from other feeders. This permits the present invention to be of an extremely more economical and efficient construction due to the low inertia forces existing during operation thereof, but more importantly, this permits the present invention to v operate upwards of 15,000 sheet feeding cycles per hour, substantially faster than similar type units heretofore known and used.

SUMMARY OF THE INVENTION This invention relates generally to work handling devices and, more particularly, to a new and improved apparatus for feeding workstock sheets such as paper, cardboard and the like, to an associated machine.

It is accordingly a general object of the present invention to provide a new and improved sheet feeding apparatus.

It is a more particular object of the present invention to provide a new and improved sheet feeding apparatus which has an extremely fast cycle time or feed rate.

It is still a more particular object of the present invention to provide a new and improved sheet feeding apparatus which utilizes a plurality of vacuum pickup elements which are mounted for rotation and pivotal movement, resulting in the elements having a compound cycle movement, whereby to minimize to the extreme the cycle time required to transfer successive workstock sheets.

It is another object of the present invention to provide a new and improved sheet feeding apparatus of the above character which utilizes a novel clutching and valving arrangement for selectively moving and transferring vacuum conditions to the pickup elements.

It is another object of the present invention to provide a new and improved sheet feeding apparatus that will find universality of application and will have a long and reliable operational life.

It is a further object of the present invention to provide a new and improved sheet feeding apparatus as above described which is of a relatively simple design, is economical to manufacture and easy to assemble.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevated perspective view of the sheet feeding apparatus of the present invention, as shown in a typical operative application in association with an index tab machine which is adapted to perform a tab cutting operation on successive workstock sheets delivered thereto by the sheet feeding apparatus of the present invention;

FIG. 2 is a top elevational view of the sheet feeding apparatus of the present invention;

FIG. 3 is a side elevational view of the sheet feeding apparatus of the present invention;

FIG. 4 is an end elevational view of the sheet feeding apparatus of the present invention;

FIG. 5 is a fragmentary side elevational view of the delivery assembly portion of the sheet feeding apparatus of the present invention;

FIG. 6 is a fragmentary top elevational view of the transfer mechanism of the sheet feeding apparatus of the present invention; I

FIG. 7 is a cross-sectional view taken substantially along the line 7-7 ofFIG. 6;

FIG. 8 is a side elevational view of the rearward side of the sheet feeding apparatus of the present invention;

FIG. 9 is a cross-sectional view taken substantially along the line 99 of FIG. 6;

FIG. 10 is a cross-sectional view taken substantially along the line 1010 of FIG. 6;

FIG. 11 is a cross-sectional view taken substantially along the line 11-11 ofFIG. 6, and

FIG. 12 is an enlarged side elevational view of the portion of the sheet feeding apparatus designated in FIG. 3 by the arrow 12.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT I. General Construction and Operational Environment Referring now in detail to the drawings and in particular to FIG. 1, a sheet feeding apparatus 10, in accordance with an exemplary embodiment of the present invention, is shown in operative association with an index tab machine 12 which constitutes no material part of the present invention and is shown herein merely for the purpose of illustrating a typical application for the sheet feeding apparatus 10 of the present invention. By way of general information, the index tab machine 12 is adapted to automatically laminate and tab cut plastic index tabs on a series of paper sheets or workstock, generally designated 14, which are selectively fed to the machine by the apparatus 10 of the present invention. The machine 12 is provided with a plurality of heated rollers, generally designated 16, which are adapted to laminate plastic index tabs to the sheets of workstock 14, which sheets 14, after traveling through the rollers 16 are subjected to the tab cutting action of a tab cutting die assembly 18 after which the sheets 14 are automatically transferred to a suitable delivery conveyor, herein designated by the numeral 20. It will be appreciated, of course, that the sheet feeding apparatus 10 of the present invention may find wide and varied application with various types of machines other than the index tab machine 12 illustrated herein, and that the present invention is to be in no way limited in scope to use with machines such as the machine 12.

For purposes of clarity of description, the terms upstream and downstream will have reference to the direction in which the sheet workstock 14 is transferred or travels through the sheet feeding apparatus 10 of the present invention, which direction of travel will be referred to as forward" or forwardly along the longitudinal axis of the apparatus 10. Similarly, the terms front" and back" will have reference to the sheet feeding apparatus 10 of the present invention as shown in FIG. 2, with the front side thereof being at the left side of this figure and the back side thereof being spaced laterally away from the front side and being located at the right side of this figure.

Generally speaking, the sheet feeding apparatus 10 of the present invention comprises three cooperative operational modes or subassemblies, namely, a sheet storage assembly or stock reservoir 22, a sheet transfer mechanism 24 which is adapted to pickup individual workstock sheets 14 from the top of a stack of sheets 14 operatively supported on the assembly 22, and a sheet delivery assembly 26 which is adapted to function in receiving successive workstock sheets 14 from the transfer mechanism 24 and thereafter deliver the same to the index tab machine 12, or to any other suitable source, delivery conveyor or the like with which the sheet feeding apparatus 10 of the present invention may be operatively associated.

II. Sheet Storage Assembly The sheet storage assembly 22 is located at the rearward or upstream end of the sheet feeding apparatus 10 and is adapted to operatively support a stack of sheet workstock which are arranged in substantially coplanar, vertically aligned relationship,'as illustrated in FIG. 1. The assembly 22 comprises an upper stack guide assembly, generally designated 28, which consists of a pair of spaced parallel longitudinally extending guide members 30 and 32 that are disposed at the front and back sides of the stack of workstock sheets 14 and are adapted to confine the workstock sheets 14 from moving toward the front and back of the apparatus 10. Disposed upon the guide members 30 and 32 is a pair of guide elements 34 and 36 which are adapted to bear against the rearward side of the stack of workstock sheets 14 and thereby limit relative longitudinal movement of the workstock sheets away from the apparatus 10. It will be noted that the elements 34, 36 are adjustably mounted upon the members 30, 32, respectively, and they may therefore be moved longitudinally to accommodate different size workstock sheets 14, as will be apparent. The longitudinally inner (forward) ends of the members 30, 32 are fixedly secured to a pair of support brackets 38 and 40, respectively, which in turn are supported for lateral adjustable movement along a transversely extending cylindrical member or shaft 42, the relative adjustable movement of the brackets 38, 40 upon the shaft 42 permitting the members 30, 32 to be biased laterally inwardly and outwardly to accommodate different size workstock sheets 14. The laterally outer ends of the shaft 42 are fixedly secured within a pair of support members 44 and 46 which are attached to the terminal ends of a pair of longitudinally extending, cylindrical-shaped rods or shafts 48 and 50, respectively, that have forward ends thereof received within a pair of longitudinally extending bores or recesses 52 and 54 of a pair of back and front side plate members 56 and 58, respectively, which are substantially coextensive of the apparatus 10.

The sheet workstock storage assembly 22 comprises an elevating mechanism, generally designated 60, upon which the stack of workstock sheets 14 is operatively supported and which is adapted to function in selectively raising the stack of workstock sheets so that the top or uppermost sheet thereof is always disposed in close proximate relation with the sheet transfer mechanism 24. The elevating mechanism 60 comprises a plurality of longitudinally extending, spaced parallel stack supporting members or tangs 62, 64 and 66, the upper edges of which are adapted to support the workstock sheets 14 in the manner illustrated in FIG. 1. The tangs 62, 64 and 66 are operatively supported by means of a pair of spaced parallel, laterally extending rods or shafts 68 and 70 which extend through suitable openings in the tangs 62-66 in the manner best shown in FIG. 1. Depending downwardly from the side members 56, 58 is a pair of spaced parallel vertically disposed members 72 and 74 between the lower ends of which is a generally horizontally disposed laterally extending cross member 76. The cross member 76 is adapted to support the lower ends of a plurality of vertically extending, spaced parallel rods 78, 80 and 82, the upper ends of which terminate and are fixedly secured directly subjacent the transfer mechanism 24. Two of the aforesaid rods, namely, the rods 80 and 82, are adapted to operatively support an elevating dolly or carriage, generally designated 84, for vertical sliding movement, which in turn effects vertical adjustable movement of the tangs 62,

64 and 66 and the stack of workstock sheets 14 supported thereon. More particularly and as best illustrated in FIGS. 3 and 4, the carriage 84 is formed with a pair of spaced parallel vertically extending bores 86 and 88 through which the rods 82 and 80, respectively, extend. The upper end of the carriage 84 is formed with a pair of spaced parallel, laterally extending bores, one of which is illustrated in FIG. 4 and designated by the numeral 90, through which intermediate or medial portions of the laterally extending rods 68 and 70 extend, thereby fixedly securing the tangs 62-66 to the carriage 84.

Means for moving the carriage 84, and hence the stack of workstock sheets 14 between raised and lowered positions, is provided by a manually actuatable adjustment wheel 92 which is disposed forwardly of a generally rectangular-shaped enclosure or housing 94 mounted on the forward side member 58, the enclosure 94 functioning as a cover means for the drive belts, gears and the like hereinafter to be described in detail which effects operation of the transfer mechanism 24. The wheel 92 is mounted on the outer end of a laterally extending shaft 96 which extends between the side members 58 and 56 and is rotatably supported thereon by suitable antifriction bearing means 98 and 100, respectively. The shaft 96 carries a suitable sprocket element 102 which is adapted to rotatably carry an elevating link-type drive chain, generally designated 104, one end of which is secured to the upper end of the carriage 84 and the lower end of which passes around a suitable idler sprocket, generally designated 106, that is mounted upon the cross member 76 (see FIG. 3), with the chain 104 extending upwardly from the sprocket 106 and being connected to the lower end of the carriage 84. As will be apparent, suitable rotational movement of the adjustment wheel 92 will effect rotation of the sprocket 106 and therefore effect raising and lowering (via the chain 104) of the carriage 84, tangs 62- 66 and stack of workstock sheets 14 supported thereon.

in order to effect automatic raising or feeding movement of the workstock stack during operation of the feeding apparatus of the present invention, the shaft 96 is adapted to be rotated by means of a cooperable, laterally extending shaft 108 which is disposed in spaced parallel relation with respect to the shaft 96 and is rotatably supported upon the side members 56, 58 by combination antifriction bearing and clutch means 110 and 112, respectively. Since the shaft 108 can only rotate in the direction shown, due to the construction of the one way clutch means 110, 112, and since the shafts 96, 108 are geared together, some means must be provided so that the pile lift carriage can be lowered for loading purposes. To accomplish this, the shaft 108 is provided with suitable drive gear 116, and the lift wheel 92 is mounted on a sleeve 115 which has a cooperable gear 114 cut in one end thereof. The sleeve 115 can be moved longitudinally on the shaft 96 so that the gear 114 can be disengaged from the gear 116 and the shaft 108. A diametrically extending pin 117 is provided through the shaft 96 which fits into suitable slots in the sleeve sembly 22 and attempts to transfer the same to the delivery assembly 26. By way of example, a typical double sheet detecting arrangement is provided on the apparatus 10 of the present invention and comprises a laterally extending shaft 122 which is rotatably secured at the opposite ends thereof to the side members 56, 58 and is provided with a plurality of laterally spaced, parallel, generally triangularly shaped fingers 124, each of which defines a generally downwardly inclined face or edge portion 126. The plurality of fingers 124 are adapted to; cooperate with a pair of roller assemblies 128 and 130 which are mounted upon a laterally extending shaft 132 and comprise roller elements 134 and 136, respectively, that are adapted to bear upon the upper surface of the sheet workstock 14 being transferred from the storage assembly 22 to the delivery assembly 26 via the transfer mechanism 24. In the position shown, an incoming sheet will pass over the shaft 122 and onto the associated sheet conveyor, but when a double" (two or more sheets) have been delivered, the shaft 122 will be rotated so that the fingers 124 mounted thereon are biased upwardly and catch the leading edges of the sheets and deflect them downwardly between a pair of generally vertically extending, longitudinally spaced parallel guide members 138, 140 to an inclined delivery tray or the like, best illustrated in FIG. 3 and designated by the numeral 142. As will be apparent, any multiple sheets of workstock which are routed via the guide members 138, 140 to the tray 142 may be removed and placed upon the stack of workstock sheets 14 in the storage assembly 22 for subsequent transferring to the delivery assembly 26. Thus, only single sheets will be fed through the machine, and whenever two or more sheets are fed at the same time, all of said sheets will be discharged to the delivery tray 142. By virtue of the fact that the double sheet detecting means hereinabove described may be of various constructions well known in the art and does not constitute a material part of the present invention, further details of the construction and operation thereof will be omitted for simplicity of description.

In operation of the assembly 22, a stack of workstock sheets 14 is operatively positioned upon the tangs 62-66, after which time the adjustment wheel 92 may be rotated some preselected amount to effect raising of the carriage 84 and 115 and thus prevents the lift wheel 92 from being rotated relative to the shaft 96. The end of the shaft 108 opposite the gear 116 is provided with a suitable one way clutch mechanism, generally designated 118, which is connected via a suitable linkage means 120, hereinafter to be described, which will effect selective rotation of the shaft 108, and hence rotation of the shaft 96 and proper vertical positioning of the workstock stack during operation of the sheet feeding apparatus of the present invention. The clutch mechanism 118, as well as the mechanisms 110, 112, may be of any suitable construction well known in the art and the details thereof will therefore be omitted for purposes of simplicity of disclosure. In order to load paper, the operator pulls the lift wheel 92 outwardly whereby to disengage the gears 116 and 114 and allow the shaft 96 to be rotated backward, thus lowering the stack. After the loading operation is completed, the operator pushes the lift wheel 92 longitudinally inward to engage the gears 114, 116, and since the shafts 96, 108 are free to rotate in the direction illustrated, the operator rotates the wheel 92 until the stack is at the proper height. The one way clutch means 110, 112 will prevent the stack from dropping.

As is conventional on sheet feeding machines adapted for feeding successive sheets of paper workstock and the like, the apparatus 10 of the present invention is provided with a double sheet detecting means which functions to sense when the sheet transfer mechanism 24 picks up two or more sheets of the workstock 14 from the stack thereof on the storage ashence the workstock sheets 14 to a position wherein the top or uppermost of the sheets 14 is in a preselected orientation with respect to the transfer mechanism 24. During operation of the mechanism 24, the linkage means will effect actuation of the clutch mechanism 118 which in turn will effect rotation of the shaft 108, as will later be described. Rotation of the shaft 108 will-in turn, via the gears 114, 116, rotate the shaft 96 whereby to cause suitable rotation of the sprocket 102 and hence upward movement of the carriage 84 so that the stack of workstock sheets 14 will be automatically raised at a preselected rate during operation of the apparatus 10 so that the uppermost sheets 14 of the stack thereof is always in position to be picked up by the transfer mechanism 24 and be transferred thereby to the delivery assembly 26. As the stack of workstock sheets 14 move upwardly by means of the carriage 84 and tangs 62-66, the stop elements 34, 36 are cooperable with a pair of similar stop or guide members 144 and 146 mounted on a laterally extending shaft 148 supported between the side members 56, 58 (see FIG. 4) to properly align the upper end of the stack of workstock sheets 14 as the successive sheets of workstock 14 are transferred to the delivery assembly 26.

It may be noted that the sheet storage assembly comprises certain conventional sheet feeding devices which are common in virtually all types of paper feeders and which are relatively essential for their effective operation, but which have not been shown in detail in the drawings. Included in such devices is the provision of a plurality of sheet separator fingers which consist of thin flexible metal members located adjacent the front edge of the stack near the point where the vacuum pickup elements grip the top sheet. In operation, these fingers provide several functions; namely, they act as a stop for the top sheet in the stack, and secondly they tend to flex or bend the top sheets slightly as they are lifted. This action tends to cause the upper sheet to be separated from the sheets therebelow, and as the top sheet is lifted, these fingers are deflected until they snap past the edge of the sheet in and over the second sheet so as to catch the second sheet and prevent any doubles."

Additionally, the feeder is equipped with nozzles for directing streams of air toward the edges of the stack at the top thereof. These streams of air function to separate the top few sheets so that when the vacuum elements grip the sheets, the space between the sheets tends to prevent gripping the second sheet by the bleed of air through the upper sheet. Secondly, the streams of air prevent a vacuum from being created from between the sheets as the upper sheet is lifted, and finally, the air tends to float the top sheet up against the aforementioned separator fingers so that even though the stack may be slightly uneven, the top-sheet is maintained in approximately the same plane at all times.

Due to the fact that the construction and operation of the aforesaid separator fingers and blow air nozzles is well known in the art, a detailed description of the construction thereof has been omitted in order to simplify the instant disclosure.

lll. Construction and Operation of Sheet workstock Delivery Assembly As best illustrated in FIG. 2, the sheet delivery assembly 26 comprises a pair of longitudinally spaced, parallel roller members 150 and 152 which extend laterally between a pair of laterally spaced, longitudinally extending support members 154 and 156 which are in turn operatively secured to the laterally inner sides of the side members 56 and 58, respectively. Means in the form of suitable antifriction bearing means or the like 158 and 159 are provided for rotatably supporting the roller members 150, 152, respectively upon the support members 154, 156, with the member 152 being provided with a suitable drive shaft member 160 extending coaxially and laterally therefrom through a suitable opening 162 in the side member 58. The shaft 160 is provided with a suitable pulley or sheave 164 around which an endless drive belt 166 extends, the drive belt 166 being operatively connected in a manner hereinafter to be described with a suitable source of motive power for effecting rotational movement of the roller member 152.

A plurality of endless conveyor belts 168, 170 and 172 extend around the roller members 150 and 152 and are adapted to be rotated in a manner such that the uppermost portions thereof which extend above the upper sides of the members 150, 152 move in a downstream direction, i.e., from right to left in FIG. 5, whereby sheet workstock l4 deposited thereof by means of the transfer mechanism 24 will be moved longitudinally downstream of the apparatus 10 toward some preselected operative destination, such as the index tab machine 12.

As best seen in FIGS. 2 and 5, disposed longitudinally interjacent the roller members 150 and 152 is a laterally extending shaft member 174 which is spaced downwardly from the plane of the members 150, 152 and is operatively supported by means of a pair of downwardly inclined support brackets 176 and 178 which are fixedly secured to the laterally inner sides of the members 156, 154, respectively. The shaft 174 is provided with three pair of laterally spaced belt guides 180, 182 and 184, each of which pair of guides has the respective guides thereof spaced laterally apart and adapted to engage the laterally opposite sides of the belts 168-172 whereby when the belts 168-172 are operatively arranged in the manner shown in FIG. wherein the lowermost portion of said belts extends around or below the lower side of the shaft 174, the respective pairs of guides 180, 182 and 184 will prevent relative lateral movement of the belts 168-172 with respect to the roller members 150 and 152. The support member 154 is provided with a plurality of holddown roller elements, generally designated 186 which are rotatably mounted on the laterally innerside thereof in longitudinally spaced positions and adapted to engage the upper surfaces of the workstock sheets 14 as the l are conveyed longitudinally of the apparatus 10 by means of the belts 168-172, with the elements 186 functioning to positively maintain the workstock sheets 14 in driving engagement with the belts 168-172 to provide for efficient conveyance thereof. As will be apparent, suitable additional or auxiliary holddown or guide roller means may be and preferably are utilized for guiding and exerting a downwardly directed force against the workstock sheets 14 as they are conveye d by means of the belts 168-172; however, such additional roller elements have been omitted in order to simplify the instant disclosure.

IV. Sheet Transfer Mechanism Generallyspeaking, the sheet transfer mechanism 24 comprises one or more vacuum pickup elements which are mounted for rotation about an axis extending laterally of the sheet feeding apparatus 10 and, together with being rotatable about said axis, is adapted to pivot between raised and lowered positions, with such rotary and pivoted movement of workstock 14 as compared to other types of sheet feeding devices heretofore known and used. More particularly and as best illustrated in FIGS. 3 and 6, the transfer mechanism 24 comprises a laterally extending drive shaft 188 which extends laterally outwardly from the side members 56, 58 and is rotatably supported thereon by suitable antifriction bearing means 190 and 192, respectively; The extreme front end of the drive shaft 188 is provided with an outwardly extending stub shaft "member 194 which projects coaxially of the shaft 188 and has a pair of drive pulleys or sheaves 196 and 198 rotatably carried thereon by means of suitable antifriction bearing means 200 and 202. The sheaves 196, 198 are secured together by suitable screws, bolts or the like 204 and are thereby adapted to rotate concomitantly relative to the shaft 188. Operatively associated with the shaft 188 and located slightly upstream therefrom is a laterally extending member 206 which is adapted to operatively support one or more vacuum pickup assemblies, two of which are utilized in the sheet feeding apparatus 10 of the present invention and generally designated by the numeral 206. As best illustrated in H6. 7, the member 206 is formed with a pair of laterally extending bores 210 and 212 which extend substantially the entire length thereof. Secured to one end of the member 206 is a stub shaft member 214 which is received with in a recess 216 in the end of the member 206 and fixedly attached thereto by suitable screws, bolts or the like 218. The stub shaft member 214 extends through an opening 220 formed in the side member 58 and is provided on the outer end thereof with a suitable sheave or pulley 222 and a cooperable slip clutch mechanism, generally designated 224, which is adapted to function in a manner hereinafter to be described. The stub shaft member 214 and hence the forward end of the member 206 is adapted to be operatively secured to the shaft 188 by means of a connecting arm 226 which is fixedly secured by suitable screws, bolts or the like 228 at one end thereof to the shaft 188 and is secured at the opposite end thereof by means of a suitable one way clutch or brake 230 to the stub shaft 2 14.

The end of the shaft 188 opposite the stub shaft 194 is fix- I edly secured by suitable screws, bolts or the like 232, to an intermediate portion 234 of a bellcrank member or arm, generally designated 236, that is mounted on the rearward or outer side of the side member 56, as best seen in FIGS. 6 and 8. The upstream end of the member 236 is adapted to be pivotably rotatably secured by means of a suitable sleeve bearing or the like 238 to a laterally extending stub shaft member 240 that has one end thereof operatively inserted within a suitable recess 242 formed in the end of the member 206 and functioning to close the ends of the bores 210, 212 extending therethrough. It will be noted that the back end of the member 206 extends through a suitable opening 246 (see FIG. 8) formed in the side member 56 to permit reciprocal movement of the member 206, and that by virtue of the fact that the arms 226 and 236 are fixedly secured to the shaft 188 and are rotatably secured to the member 206, upon pivotal movement of the shaft 188, the member 206 and pickup assemblies 208 supported thereon will be moved between raised and lowered positions, while permitting the member to be freely rotatable relative to the arms 226, 236. Such means for selectively ivoting or reciprocating the member 206 and the assemblies 208, as well as the means for selectively rotating the member 206 will be hereinafter described in detail.

Mounted on the outer or rearward side of the arm 236 by means of suitable screws, bolts or the like 248 is a generally rectangularshaped member 250 which is formed with an elongated bore or passage 252 closed at one end thereof by a suitable closure plug or the like 254. The passage 252 is communicable with a pair of internally threaded cross bores 256 and 258, the former of which is adapted to have threadably connected thereto a suitable vacuum conduit 260 which is in turn adapted to be connected with a suitable source of vacuum pressure (not shown). The cross bore 258 is adapted to threadably receive one end of a suitable vacuum conduit or pipe 262 which extends through a bore 264 in the arm 236 and a suitable opening 266 in the side member 56. The conduit 262 defines a central bore or passage 268 which is communicable with a generally longitudinally extending conduit 270, one end of which is connected to the conduit 262 by means of a suitable connecting member or fitting 272. The end of the conduit 270 opposite that which is communicable with the conduit 262 is threadably received within a radially extending bore 274 formed in an outer sleeve member 276 of a rotatable union assembly, generally designated 277. The bore 274 is communicable with an annular passage or recess 278 formed around the inner periphery of the member 276, which recess 278 is communicable with a suitable bore or passage 280 formed in an annular sleeve-like member 282 defining a central bore 284 within which one end of the member 206 is rotatably disposed. As illustrated in FIG. 9, the portion of the member 206 which is rotatably disposed within the member 282 is formed with a pair of enlarged counterbores 286 and 288 which are communicable with the bores 210, 212, respectively. It will be seen that when the conduit 260 is connected to a suitable source of vacuum pressure, the vacuum conditions prevalent at said source will be communicated through the conduit 260, passage 252 and conduits 262 and 270 to the interior of the annular recess 278. Upon rotation of the member 206, the counterbores 286, 288 will alternatively rotate into registry with the bore 280, whereby the vacuum conditions existing within the recess 278 will be communicated first to one of the bores 210 or 212 and then to the other of said bores. It will be noted that when one of the bores 210 or 212 is communicable with the vacuum source, the other of said bores remains sealed since the inner periphery of the member 282 will close or cover the counterbore associated with said other bore 210 or 212.

Referring now in detail to the construction and operation of the vacuum pickup assemblies 208, it will be noted that the sheet feeding apparatus 10 of the present invention utilizes two of the assemblies 208 which are preferably identical in construction and operation so that the following description, while being specifically directed toward the assembly illustrated in FIG. 10 will be applicable to the other of said assemblies 208. As best seen in FIGS. 6, 10 and 11, the member 206 is formed with a plurality of enlarged cross-sectioned portions 290 which are generally rectangular in shape and each of which defines faces 292, 294, 296 and 298. The faces 292 and 296 of each of the portions 290 are formed with inwardly extending bores 300 and 302, the inner ends of which connect with the bores 212 and 210, respectively. The faces 294 and 298 of each of the portions 290 are formed with inwardly extending bores 304 and 306, respectively, which intersect the bores 300 and 302, respectively, and are adapted to threadably receive suitable locking screws or the like, generally designated 308. It will be appreciated that the number of vacuum pickup assemblies 208 with which the apparatus 10 is provided may vary, depending upon the size and type of sheet workstock 14 being handled thereby. While each of the portions 290 on the member 206 is adapted to constitute one of the pickup assemblies 208, only two of said portions 290 have been utilized for a pickup assembly 208, while the remainder of the portions 290 have been provided with temporary sealing means for blocking communication between the bores 210, 212 and the atmosphere, with such sealing means being readily removable and thereby being adapted for use as a pickup assembly transferring the sheet workstock 14. Such sealing means is illustrated in FIG. 11 as comprising a pair of closure plugs 310 which are adapted to be inserted within the bores 300, 302 and be provided with suitable O-ring sealing means or the like 312. The plugs 310 are formed with suitable peripheral recesses 314 which are adapted to receive retaining detents 316 formed on the ends of the locking screws 308 for positively securing the plugs 310 in their respective operative positions shown in FIG. 11.

Each of the vacuum pickup assemblies 208 comprises a pair of vacuum pickup elements 317, each of which includes a tubular member 318 having its inner end inserted within one of the bores 300, 302, the members 318 being formed with suitable recesses 320 adapted for engagement by the retaining detents 316 of the lock screws 308 for positively securing the members 318 in place. The outer ends of the members 318 are adapted to be inserted within the ends of outwardly projecting, resilient sleeve-like members 322 which are preferably fabricated of a resilient elastomeric material such as rubber or the like and are provided with internal rigidifying coil springs or the like 324 that are axially deformable but which yieldably resist inward movement of hollow tubular nozzle members 326 that are located at the outer ends of the elements 317. As will be apparent, the members 322 are adapted to sealingly engage the outer periphery of the members 318 and nozzles 326 to positively assure against any vacuum leakage therebetween. The outer ends of the nozzles 326 define annular pickup faces 328 which are adapted to detachably engage the successive sheets of workstock 14 that are maintained in contact therewith by virtue of the vacuum conditions which are transmitted to the nozzle members 326 through the bores 210, 212, as will be apparent. The purpose of the yieldable or resilient interconnection between the nozzles 326 and the members 318 is to permit a certain amount of movement of the nozzle 326 toward the member 206 in the event the uppermost of the sheets of workstock 14 is disposed at a slightly higher level than the workstock level shown, for example, by the phantom line 329 in FIG. 10.

The vacuum pickup elements 317 of each of the assemblies 208 are circumferentially aligned with one another so that upon rotation of the member 206, two of the elements 317 will move into engagement with the uppermost of the workstock sheets 14, these two elements 317 being connected via one of the bores 210 or 212 and the passage 280 to the source of vacuum, whereby the elements 317 which are engaged with the workstock sheets will pickup the uppermost sheet 14 and cause the same to move with the member 206 as it rotates and is pivoted via the arms 226 and 236, as will be described. After the aforesaid two pickup elements 317 are disengaged with the uppermost sheet, the opposite two elements 317 on the pickup assemblies 208 will rotate clue to rotation of the member 206 into engagement with the next successive uppermost workstock sheet 14, and as these two elements 317 move into confronting relationship with the workstock sheets 14, the passage 280 moves into registry with the associated bores 210 or 212 communicating the source of vacuum therewith, while the other of the bores 210 or 212 associated with the opposite pickup elements 317 moves out of registry with the passage 280 to preclude communication of the vacuum source therewith. Thus, the two pickup elements 317 which move into confronting relationship with the stack of workstock sheets 14 are placed in communication via one of the bores 210 or 212 with the source of vacuum while the opposite two pickup elements 317 are out of communication with the vacuum source, and upon continued rotation of the member 206, said opposite two pickup elements 317 will move into confronting relationship with the workstock sheets 14 and will be placed in communication with the vacuum source while the first two elements 317 will revolve away from the workstock sheets 14 and will be out of communication with the vacuum source. In order to assure positive pickup action of the pickup elements 317 with the successive sheets of workstock 14, means is provided on the rotatable member 206 to temporarily or briefly stop rotation thereof at the moment the pairs of pickup elements 317 move into confronting relationship with the sheets 14, thereby permitting each cooperating pair of elements 317 to pause momentarily during rotation thereof as the vacuum conditions communicated to the nozzle faces 328 thereof effect picking up of the uppermost of the sheets 14. Such means for intermittently stopping rotation of the member 206 and hence the assemblies 208 thereon is in the form of a pair of radially outwardly extending stop fingers 330 and 332 which are preferably fabricated of a resilient or spring material such as spring steel or the like and are fixedly secured by means of suitable screws, bolts or the like 334 to a support block 336 that is fixedly secured to the stub shaft member 214 and is rotatably positioned thereon so that the fingers 330, 332 will engage a laterally extending shaft member 338 that is disposed between the side members 56, 58 at the exact time two of the pickup elements 317 move into confronting relationship with the stack of workstock sheets 14. That is, one of the fingers 330, 332 will engage the shaft 338 and stop rotation of the member 206 when one of the pairs of elements 317 confront the workstock stack and the other of the fingers 330, 332 will engage the shaft 338 and stop rotation of the member 206 when the other of the pair of elements 317 move into confronting relationship with the workstock stack. The function of the resilient or yieldable construction of the fingers 330, 332 is such that said fingers will serve as a shock absorbing medium and thereby absorb at least a portion of the force or momentum of the rotating member 206 and assemblies 208 thereon as the successive fingers 330, 332 engage the shaft 338. It will be noted that the function of the one way clutch 230 interconnecting the arm 226 with the stub shaft 214 and hence with the member 206 is to prevent any reverse rotation of the member 206 and assemblies 208 due to the reaction created by the sudden engagement of the fingers 330, 332 with the shaft 338. It will be appreciated, of course, that the use of the clutch 230 may be omitted under certain circumstances wherein the construction of the stop fingers 330, 332, or equivalent stop means, is such as to assure against any reverse rotation of the member 206. In operation of the sheet feeding apparatus of the present invention, rotational power is transmitted to the member 206, and hence to the assemblies 208, by means of a suitable drive belt 340 which extends around the sheave or pulleys 196 and 222, with the rotary motion imparted to the sheave 222 being transmitted via the slip clutch 224 to the stub shaft 214 and the member 206. The provision of the slip clutch 224 permits continued rotation of the sheave 222 via the drive belt 340 during such time as rotational movement of the member 240 is temporarily or intermittently stopped due to interengagement of the stop fingers 330, 332 with the shaft 338. As will be described in connection with the overall operation of the sheet feeding apparatus 10 of the present invention, pivotal movement of the member 206 due to pivoting of the arms 226, 236 about the axis of the shaft 188 will efiect disengagement of the stop fingers 330, 332 with the shaft 338 so that as the member 206 pivots upwardly during the transfer cycle, the particular finger 330 or 332 which is engaged with the shaft 338 will become disengaged therefrom so that rotation of the member 206 will be resumed.

It may be noted that while each of the assemblies 208 is shown as being provided with two of the pickup elements 317 and the member 206 being shown with a corresponding number of bores 210, 212 through which the vacuum source is communicated to the elements 317, the present invention is not intended to be limited to this particular construction since the number of pickup elements 317 of each of the assemblies 208 may be more or less than the number shown herein, depending upon the particular application of the apparatus 10. Accordingly, while the apparatus 10 is preferably provided with two pickup elements 317 on each of the pickup assemblies 208, and the member 206 is preferably provided with two bores for communicating vacuum conditions thereto, substan tial variation from this preferred construction is contemplated by the scope of the present invention.

The sheet feeding apparatus 10 of the present invention may be powered by any suitable means, such as by an electric motor, which may operate independently from the associated index tab machine 12 or be operatively associated with the machine 12 so that a single motor (not shown) will operate both the apparatus 10 and the machine 12. Such source of motive power is adapted to be communicated by any suitable means known in the art, preferably a drive chain or the like, to a drive shaft 342 which extends between the side members 56, 58 and is rotatably supported thereon by suitable antifriction bearing means or the like (not shown). The shaft 342 is provided with a suitable drive sprocket 344 which is adapted to cooperate with a similar sheave or pulley 346 provided on another transversely extending shaft 348 that extends between and is rotatably supported at the opposite ends thereof by the side members 56, 58. Besides the sheave 346, the shaft 348 is provided with another drive sheave or pulley 350 around which the drive belt 166 is carried, with a suitable idler roller or the like 352 being provided interjacent the sheaves or pulleys 350 and 164, as shown in FIG. 3. Additionally, the drive shaft 348 is adapted to carry a suitable drive gear 354 which is meshingly or drivingly engaged with a cooperative drive gear 356 that is mounted on a suitable drive shaft 358 that extends between and is rotatably supported between side members 56, 58. The drive sheaves or pulleys 344, 346 are adapted to carry and be drivingly connected by means of a suitable drive belt 360 which functions to transmit rotary movement from the drive shaft 342 to the drive shafts 348 and 358 via the gears 354, 356. The drive shaft 358 is provided with a suitable sheave or pulley 362 which cooperates with the pulley 198 to rotatably support a suitable drive belt 364 which communicates rotational movement of the drive shaft 358 to the sheaves 196, 198, and hence imparts rotary movement to the member 206 via the drive belt 340.

As best seen in FIGS. 2 and 3, disposed downstream from the shaft 338 is a pair of laterally extending feed rollers 366 and 368 that are rotatably supported by and extend between the side members 56, 68 and are provided at the outer or forward ends thereof with suitable drive sheaves 370 and 372, respectively, around which the drive belt 166 extends, a suitable idler pulley or the like 374 being provided interjacent the sheaves 164 and 372 for properly tensioning the drive belt 166, as will be apparent. With this arrangement, it will be seen that upon rotation of the shaft 348, the drive belt 166 will move in the direction of the arrow 376 in FIG. 3, thereby effecting rotation of the roller member 152 and concomitant rotation of the feed rollers 366, 368, while rotation of the shaft 348 will effect simultaneous rotation of the shaft 358 which in turn effects movement of the drive belt 364 in the direction of the arrow 376 in FIG. 3, thereby causing concomitant rotation of the belt 340 and resulting in rotation of the member 206 and vacuum pickup assemblies 208 thereon.

Referring now to FIG. 8, mounted on the rearward end of the shaft 358 is an eccentric cam member 378 which is fixedly secured for rotation with the shaft 358 and defines an eccentric or flat 380 around the outer peripheral edge thereof. The

cam member 378 is provided with an outwardly extending pivot pin 382 to which a suitable clevis or pivot fitting 384 is pivotably connected, which fitting 384 is connected through suitable take-up linkage means 386 and 388 with another fitting 390 which is pivotably connected by means of a suitable pivot pin or the like 392 with a downwardly inclined end portion 394 of arm 236. It will be seen that the pivot pin 382 is eccentrically oriented with respect to the axis of the rotation of the shaft 358 so that as the shaft 358 rotates, the end portion 394 will be reciprocated upwardly and downwardly through movement of the linkage means 386, 388, and by virtue of the fact that the stub shaft 240 connects the member 206 with the end of the arm 238 opposite the end portion 394, upward and downward movement of the end portion 394 of the arm 236 will effect simultaneous reciprocal movement in the opposite direction of the member 206 toward and away from the top or upper end of the stack of workstock sheets 14 and the feed rollers 366, 368 to which the sheets of workstock 14 are delivered by the vacuum pickup assemblies 208. The connecting linkage 388 provides two functions, the first of which is the adjustment which is indicated. The second is a safety feature. If for some reason there is an interference in the pickup area (say that the member 206 is out of radial position so that the stop fingers would come down on top of roller 338 instead of in front of it), the elements 388 and 386 form a sliding connection so that in case of an interference, the member 206 will not be forced down damaging it. It will be appreciated, of course, that the angular position of the pivot pin 382 on the cam member 378 is such that upward and downward reciprocal or pivotal movement of the member 206 is properly timed or sequenced with rotation of the member 206 so that the pickup elements 317 are placed in communication with the vacuum source at the proper time sequence as the elements 317 move to and from confronting relationship with the stack of workstock sheets 14. It will be noted that the timing of the rotation of the nozzles with respect to the up and down motion of the member 206 is a function of the time of release of the stop fingers from roller 338 and also of the driven speed of member 206. This timing is entirely automatic, and if the unit is thrown out of time, it will automatically regain it in about 1 to 2 cycles.

As best seen in FIG. 8, the clutch mechanism 118 is connected via a suitable arm 395 to a pivot pin 396 extending through a clevis or fitting member 398 fixedly secured to the lower end of the linkage means 120. The end of the arm 395 opposite the pivot pin 396 is provided with a cam roller or follower 400 which is adapted to bear against or peripherally engage the cam member 378, whereby rotational movement of the member 378 in the direction of the arrow 402 in FIG. 8 will effect reciprocal movement of the arm 395 about the axis of rotation of the shaft 108. The upper end of the linkage means 120 is connected through a suitable fitting or clevis member 404 and pivot pin 406 to a longitudinally extending arm section 408 of a laterally extending shaft member 410 which projects through a suitable opening 412 formed in the side member 56 and is rotatably or pivotably supported thereon by means of a suitable pivot support bracket 414. The shaft 410 has an eccentric pin 413 projecting from the end thereof, which pin 413 supports the arm section 408. As best seen in FIG. 2, extending upstream or toward the assembly 22 from the shaft member 410 and integrally connected thereto is an arm section 416 which is adapted to reciprocate upwardly and downwardly in the opposite direction from the arm section 408 upon upward and downward movement of the link age means 120 in response to rotation of the cam member 378. The arm section 416 is adapted to operatively support the rearward end of a laterally extending sheet level sensing rod 418 which is adapted to bear against the uppermost workstock sheet 14 of the stack thereof on the storage assembly 22 and thereby function in the manner to be described in connection with the overall operation of the sheet feeding apparatus of the present invention. The shaft 410 is provided with an outwardly projecting, manually engageable handle or knob 420, and it will be seen that rotation of the shaft 410 by means of the knob 420 changes the height of the pivot point for the arm section 408. Changing the pivot point of the arm 408 will in turn change the height-that the stack of paper will rise to, and this is important since different stock feeds differently and feeding conditions can even change within a single load due to warpage of the stock. With the present arrangement, the operator can change the pile height without stopping the feeder.

V. Operation In operation of the sheet feeding apparatus 10 of the present invention, assuming the initial conditions that the sheet storage assembly 22 is provided with a suitable stack of workstock sheets 14 and that suitable drive means in the form of an electrical motor or the like is effecting rotational movement of the drive shaft 342 in a counterclockwise direction in FIG. 3, such movement of the drive shaft 342 will efiect rotation of the drive belt 360 in a counterclockwise direction in FIG. 3, thereby causing the sheave 346 to rotate counterclockwise. Such rotation of the sheave 346 will effect rotation of the drive belt 166 in the direction of the arrow 376, i.e., counterclockwise, in FIG. 3, while the interaction of the gears 354 and 356 will effect clockwise rotation of the drive shaft 358 and clockwise rotation of the drive belt 364. The aforesaid rotation of the shaft 358 will effect concomitant rotation of the cam member 378 which will therefore rotate in the direction of the arrow 402 in FIG. 8. Rotation of the drive belt 364 will effect clockwise rotation of the drive belt 340 which will result in rotation of the member 206 and vacuum pickup assemblies 208 in the same direction. Likewise, the aforesaid counterclockwise rotation of the drive belt 166 will effect counterclockwise rotation of the feed rollers 366 and 368, as seen in FIG. 3.

Upon rotation of the member 206, two of the vacuum pickup elements 317 will move downwardly toward engagement with the uppermost of the workstock sheets 14 until such time as the associated of the stop fingers 330 or 332 moves into engagement with the shaft member 338, thereby temporarily stopping rotation of the two pickup elements 317 as they move into engagement with the uppermost of the sheets 14. Due to the communication of the source of vacuum with these two elements 317 via one of the bores 210 or 212 and the union assembly 277, the uppermost of the workstock sheets 14 will be picked up by the confronting pickup elements 317. By virtue of the rotation of the cam member 378, the arm 236 will effect, in preselected timed relationship, upward movement of the member 206, as well as the assemblies 208 thereon and the uppermost of the workstock sheets 14, whereby the leading edge of the workstock sheet 14 is biased upwardly and forwardly and inserted interjacent the rotating feed rollers 366, 368 and the roller assemblies 128, 130, which efiect removal or stripping the workstock sheet 14 from the pickup elements 317 engaged therewith and transferring the same downstream of the apparatus 10 toward engagement with the conveyor belts 168-172 which are in turn rotating due to rotation of the drive belt 166. In particular, the leading edge of the sheet is bent into a horizontal position, thus pulling it free from the vacuum pickup elements and eliminating the need for valving to release the sheets. The subject workstock sheet will consequently be conveyed or transferred downstream for delivery to the associated index tab machine 12 or the like.

As the member 206 moves upwardly due to the pivoting action of the arm 236, the particular stop finger 330 or 332 theretofore engaged with the roller 338 will move out of engagement with the shaft member 338, whereby to permit continued rotation of the member 206 due to the action of the slip clutch mechanism 224 and drive belt 340, thereby causing the diametrically opposite pickup elements 317 to move or rotate downward into engagement with the next successive workstock sheet 14 to be transferred in the same identical manner herein described.

Due to the rotation of the cam member 378, the arm 395 will reciprocate about the axis of the shaft 108 as the cam follower 400 rides across the flat 380 of the member 338. Such reciprocal movement of the arm 395 will effect selective rotation of the shaft 108 via the clutch mechanism 118, resulting in rotation of the chain 104 carrying the dolly or carriage 84 and resulting in automatically elevating the stack of workstock sheets 14. The function of the rod 418 is to sense the level or height of the uppermost workstock sheet 14 and in normal operation, with the stack below the normal feed height, the

arm 395 is allowed to travel a complete or full cycle. As the cam follower nears the center of the flat section of the cam 378, a dog arrangement (not shown) on the arm 395 contacts a cooperable dog (not shown) on the one way clutch assembly 118. Further rotation of the arm 395 rotates the clutch clockwise which is the free travel direction of the assembly 118. Then, as the arm 396 is rotated in the opposite direction by the cam follower rolling off of the cam flat" and onto the eccentric section of the cam 378, the dog on the arm engages the dog on the clutch assembly 118 and causes it to be rotated in the opposite direction from which it was originally rotated. When the assembly 108 is turned in this direction, the shaft 108 is driven or rotated by the assembly 118. At such time as the stack approaches the feed height, the rod 418 begins to engage the top of the stack which prevents the arm section 416 from making a complete stroke. This, in turn, limits rotation of arm 395 so that the cam follower will come off from contact with the cam 378. The travel of the arm 395 causes less movement of the clutch assembly 118 and thus cuts down the lift of the stack. In actual operation, the stack height will drop about 2-3-sheet thicknesses before the mechanism will lift, and when feeding is stopped, the stack height will gradually move upwards about 2-3-sheet thicknesses before coming to a complete stop.

While it will be apparent that the preferred embodiment illustrated herein is well calculated to fulfill the objects above stated, it will be appreciated that the present invention is susceptible to modification, variation and change without departing from the scope of the invention.

I claim: a

I. In an apparatus for feeding successive sheets of workstock from a stack or pile thereof, a sheet storage assembly adapted to operatively support the stack of workstock sheets; a delivery assembly for conveying successive sheets of workstock to an associated machine or other operation destination where the workstock sheets are to have some operation performed thereon; and a transfer mechanism for individually transferring successive workstock sheets from said sheet storage assembly to said delivery assembly, said transfer mechanism including at least one vacuum pickup element, first means supporting said element for compound movement about rotational and pivotal axes extending transversely of the path of movement of the workstock sheets, and second means including a resilient finger carried by said first means for interrupting movement of said pickup element relative to said rotational axis.

2. The invention as set forth in claim 1 wherein said transfer mechanism comprises first and second members extending transversely of the path of the workstock'sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member.

3. The invention as set forth in claim 2 wherein said second member is rotatable relative to said first member.

4. The invention as set forth in claim 2 wherein said second member is pivotable about a transverse axis extending coaxially of said first member.

5. The invention as set forth in claim 2 wherein said second member includes means defining a vacuum passage communicating said pickup element with a source of vacuum pressure.

6. The invention as set forth in claim 5 which includes valve means selectively opening and closing a circuit between said vacuum source and said vacuum pickup element, whereby said source is communicated with said element and is moved toward and into engagement with successive workstock sheets.

7. The invention as set forth in claim 5 which includes first and second vacuum pickup elements on said second member, and means defining first and second passage means extending longitudinally of said second member, one of said first passage means being communicable with one of said elements and said second passage means being communicable with the other of said elements.

8. The invention as set forth in claim 7 which includes valve means selectively communicating said vacuum source alternatively with said first and second passage means.

9. In an apparatus for feeding successive sheets of work stock from a stack or pile thereof, a sheet storage assembly adapted to operatively support the stack of workstock sheets, a delivery assembly for conveying successive of workstock to an associated machine or other operation destination where the workstock sheets are to have some operation performed thereon, and a transfer mechanism for individually transferring successive workstock sheets from the stack thereto to the delivery assembly, said transfer mechanism including at least one vacuum pickup element, first and second members extending ,transversely of the path of the workstock sheets; and wherein said second member is rotatable relative to said first member, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member, and stop means for resisting rotational movement of said second member as said pickup element moves toward and into engagement with successive workstock sheets.

10. The invention as set forth in claim 9 wherein said stop means comprises resilient finger means extending from said second member and rotatable therewith and oriented with respect to said pickup element to resist rotation of said second member as said pickup element moves into engagement with successive workstock sheets.

11. In apparatus for feeding successive sheets of workstock, means for supplying successive sheets of workstock, a delivery assembly for conveying successive sheets of workstock to an associated machine or other operative destination, a transfer mechanism for individually transferring successive workstock sheets from said storage assembly to said delivery assembly, said transfer mechanism including rotatable shaft means and at least one vacuum pickup element mounted on said shaft means for rotation about an axis extending transversely of the path of movement of the workstock sheets and being movable between first and second positions, valve means selectively communicating a vacuum source to said element as the same travels between said positions and means carried on and rotatable with said shaft means for varying the rate of rotational movement of said vacuum pickup element in response to said element being in one of said first and second positions.

12. The invention as set forth in claim 11 wherein said transfer mechanism comprises first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member.

13. The invention as set forth in claim 12 which includes means for storing a stack of workstock sheets and for elevating the same in a manner such that the uppermost sheet of said stack thereof is disposed in a preselected orientation with respect to said transfer mechanism.

14. The invention as set forth in claim 13 wherein said elevating means is actuatable in response to movement of one of said members.

15. The invention as set forth in claim 13 which includes level sensing means for ascertaining the vertical height of the uppermost sheet'of said stack thereof on said storage means.

16. The invention as set forth in claim 15 which includes clutch means drivingly connecting said elevating means with one of said first mentioned members, and wherein said leveling sensing means includes means engageable with the stack of workstock sheets for controlling actuation of said clutch means.

17. In an apparatus for feeding successive sheets of workstock, means for supplying successive sheets of workstock, a delivery assembly for conveying successive sheets of workstock to an associated machine or other operative destination, a transfermechanism for individually transferring successive workstock sheets from said storage assembly to said delivery assembly, said transfer mechanism comprising at least one vacuum pickup element, first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member and being movable between first and second positions, valve means selectively communicating a vacuum source to said element as the same travels between said positions and stop means for yieldably resisting rotational movement of said second member as said pickup element moves toward successive workstock sheets.

18. The invention as set forth in claim 17 wherein said stop means comprises resilient finger means extending from said second member and rotatable therewith and oriented with respect to said pickup element to resist rotation of said second member as said pickup element moves toward successive workstock sheets.

19. The invention as set forth in claim 18 which includes clutch means for drivingly connecting said second member with a source of motive power when said finger means stops rotation of said pickup element mounted on said second member.

20. The invention as set forth in claim 18 which includes clutch means for preventing reverse rotation of said second member upon engagement of said finger means with an associated stop member.

21. In an apparatus for feeding sheet workstock, at least one pickup element adapted for releasable engagement with successive workstock sheets; means for operatively supporting said pickup element including a transfer member movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination; means for gradually stopping movement of said transfer member in said first position in order to absorb the momentum of movement thereof; and means for moving said transfer member and said pickup element supported thereon along a preselected path.

22. The invention as set forth in claim 21 wherein said compound movement of said transfer member and said pickup element supported thereon is defined by pivotal and rotational movement of said transfer member about parallel axes extending substantially transversely of the direction of movement of the workstock sheets.

23. The invention as set forth in claim 21 wherein said operatively supporting means further includes a first member extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first member and said transfer member.

24. The invention as set forth in claim 23 wherein said transfer member is rotatable relative to said first member.

25. The invention as set forth in claim 23 wherein said transfer member is pivotable about a transverse axis extending parallel of said first member.

26. The invention as set forth in claim 25 which includes a plurality of vacuum operated pickup elements, and means on said transfer member defining a plurality of vacuum passages corresponding one to each of said elements.

27. The invention as set forth in claim 26 which includes valve means selectively opening and closing a circuit between a vacuum source and said passage means, said valve means thereby automatically communicating said vacuum source with the particular pickup element disposed closest to the sheet workstock when said transfer member is disposed in said first position, while blocking communication between said vacuum source and those pickup elements which are spaced away from the sheet workstock.

28. The invention as set forth in claim 21 wherein said means for gradually stopping movement includes finger means supported by'said transfer member, and interferring means for engaging said finger means in said first position of said transfer member.

29. The invention as set forth in claim 28, wherein said interferring means is a shaft extending transversely of the path of the workstock sheets.

30. The invention as set forth in claim 28 wherein said finger means comprises a sleeve connected to said transfer member and at least one radially extending finger member having one end connected to said sleeve.

'31. The invention as set forth in claim 30 wherein said finger member is fabricated from a resilient material 30, provide a shock absorbing function upon contact of said finger with said shaft.

32. In an apparatus forfeeding sheet workstock, at least one pickup element adapted for releasable engagement with successive workstock sheets; means for operatively supporting said pickup element including a transfer member movable betweenl a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination; means for moving said transfer member and said pickup element supported thereon along a compound curved path, said compound curved path of said transfer member and said pickup element supported thereon being defined by pivotal and rotational movement of said transfer member about parallel axes extending substantially transversely of the direction of movement of the workstock sheets; and which includes stop means for resisting rotational movement of said transfer member as said pickup element moves toward and into engagement with successive workstock sheets.

33. The invention as set forth in claim 32 which includes elevating means actuatable in response to movement of said transfer {member for raising a stack of workstock sheets toward said pickup elements.

34. The invention as set forth in claim 29 wherein said stop means yieldably resists rotational movement of said transfer member as said pickup element moves toward engagement with successive workstock sheets, said stop means comprising a stop member, resilient finger means extending from said transfer member and rotatable therewith and oriented with respect to said pickup elements and engageable with said stop member to preclude rotation of said transfer member as said pickup elements move into engagement with successive workstock sheets, and wherein said means for moving said transfer member includes clutch means for drivingly connecting said transfer member with a source of motive power when said finger means stops rotation of said pickup element, and prevents reverse rotation of said transfer member upon en gagement of said finger means with said stop member.

35. In an apparatus for feeding sheet workstock, at least one rotatable pickup element having at least two nozzles, each nozzle being adapted for releasable engagement with successive workstock sheets, means for operatively supporting said pickup element including rotatable shaft means movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination, said shaft means defining a number of longitudinally interiorly extending passages conforming to the number of said nozzles, each passage being in communication with one of said nozzles; and valve means for individually communicating a vacuum source to one of said passages while blocking said source from the remainder of said passages.

36. The invention as set forth in claim 35, wherein said valve means is comprised of a tubular sleeve having a radially extending aperture and rotatably supported by said shaft means, and wherein said shaft means includes a number of transversely extending passages, each passage being in communication with one of said longitudinally extending passages.

37. The invention as set forth in claim 36, wherein said radially extending aperture is in communication with a source of vacuum and wherein said source is communicable to one of said transversely extending passages via said aperture by relative rotation between said shaft means and said sleeve.

38. The invention as set forth in claim 37, further including a rotary union for connecting said valve means with the vacuum source.

39. The invention as set forth in claim 35 wherein said pickup element includes at least two transversely extending bores relative to said shaft means, each of said bores being in communication with one of said longitudinally extending passages.

40. The invention as set forth in claim 39, wherein each of said nozzles is comprised of a first tubular section adapted to be removably inserted in one said bores, a second tubular section adapted to engage a workstock sheet, and a third tubular section slidably interposed between said first and second tubular sections.

41. The invention as set forth in, claim 40 further including a spring member located in said tubular section to bias said second tubular section relative to said workstock sheet.

42. The invention as set forth in claim 39, wherein each of said bores may be selectively plugged.

43. The invention as set forth in claim 35, including a plurality of pickup elements operatively supported by said shaft I means, and wherein some of said pickup elements are selectively plugged.

44. In an apparatus for feeding sheet workstock, at least one I rotatable pickup element adapted for releasable engagement with successive workstock sheets, means for operatively sup porting said pickup element including a transfer mechanism movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination, said mechanism including relatively rotatable means adapted for selective engagement with relatively nonrotatable means for interrupting rotation of said pickup element at said first position, and

means for storing a stack of workstock sheets and for moving the same in response to movement of said transfer mechanism whereby preselected sheets of said stock are disposed in a preselected orientation with respect to said pickup element.

45. The invention as set forth in claim 44, wherein said transfer mechanism comprises first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member.

46. The invention as set forth in claim 45, wherein said second member is rotatable relative to said first member and wherein said second member is pivotable about a transverse axis extending parallel of said first member.

47. The invention as set forth in claim 46, which includes a plurality of vacuum operated pickup elements, and means on said second member defining a plurality of vacuum passages corres nding one to each of said elements.

48. The invention as set forth in claim 45, further including cam means for operatively oscillating said second member between said first and second positions, and first linkage means for operatively connecting said cam means to said means extending between and operatively connecting said first and second member.

49. The invention as set forth in claim 48, further including sheet level sensing means for sensing the level of the workstock sheets relative to said first position of said pickup element.

50. The invention as set forth in claim 49, further including second linkage means for operatively connecting said sheet level sensing means to said cam means l. The invention as set forth in claim 46 wherein said cam means is a rotatable disc having a fiat, and wherein said second linkage means includes a rotatable arm having one end displaceable about the outer periphery of said rotatable disc.

52. The invention as set forth in claim 51 wherein said first linkage means includes an arm having one end eccentrically connected to said rotatable disc and an opposite end connected to said operatively connecting means.

53. The invention asset forth in claim 51 wherein said operatively connecting means includes a bellcrank having one end rotatably connected to said second member and having an intermediary portion connected to said first member.

54. The invention as set forth in claim 53, further including cam means for effecting movement of an opposite end of said bellcrank.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 663, 009 Dated May 16, 1972 InventorCs) Joe Scott It is certified that error appears in the above-identified patent and that I said Letters Patent are hereby corrected'as shown below:

Column 8, line 48, "206" should be -208--'-. Column 12, line 56,

"68" should be "58-". Column 13, line 13, "238" should be -236-. Column 16, line 17, after "successive" insert -sheets-. Column 18, claim 31, line 2, after "material" delete "30, and insert therefor -to-. Column 20, claim 51, line 30, "46" should be "48" and claim 53,

line 38, "51" should be --45-.

Signed and sealed this 6th day of March 1973.

(SEAL) Attest:

EDWARD M-FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents :ORM PC4050 (0459) USCOMM-DC scam-ps9 a U 5v GOVERNMENT FRINTING OFFlCE '99 0356-J3l 

1. In an apparatus for feeding successive sheets of workstock from a stack or pile thereof, a sheet storage assembly adapted to operatively support the stack of workstock sheets; a delivery assembly for conveying successive sheets of workstock to an associated machine or other operation destination where the workstock sheets are to have some operation performed thereon; and a transfer mechanism for individually transferring successive workstock sheets from said sheet storage assembly to said delivery assembly, said transfer mechanism including at least one vacuum pickup element, first means supporting said element for compound movement about rotational and pivotal axes extending transversely of the path of movement of the workstock sheets, and second means including a resilient finger carried by said first means for interrupting movement of said pickup element relative to said rotational axis.
 2. The invention as set forth in claim 1 wherein said transfer mechanism comprises first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member.
 3. The invention as set forth in claim 2 wherein said second member is rotatable relative to said first member.
 4. The invention as set forth In claim 2 wherein said second member is pivotable about a transverse axis extending coaxially of said first member.
 5. The invention as set forth in claim 2 wherein said second member includes means defining a vacuum passage communicating said pickup element with a source of vacuum pressure.
 6. The invention as set forth in claim 5 which includes valve means selectively opening and closing a circuit between said vacuum source and said vacuum pickup element, whereby said source is communicated with said element and is moved toward and into engagement with successive workstock sheets.
 7. The invention as set forth in claim 5 which includes first and second vacuum pickup elements on said second member, and means defining first and second passage means extending longitudinally of said second member, one of said first passage means being communicable with one of said elements and said second passage means being communicable with the other of said elements.
 8. The invention as set forth in claim 7 which includes valve means selectively communicating said vacuum source alternatively with said first and second passage means.
 9. In an apparatus for feeding successive sheets of workstock from a stack or pile thereof, a sheet storage assembly adapted to operatively support the stack of workstock sheets, a delivery assembly for conveying successive of workstock to an associated machine or other operation destination where the workstock sheets are to have some operation performed thereon, and a transfer mechanism for individually transferring successive workstock sheets from the stack thereto to the delivery assembly, said transfer mechanism including at least one vacuum pickup element, first and second members extending transversely of the path of the workstock sheets, and wherein said second member is rotatable relative to said first member, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member, and stop means for resisting rotational movement of said second member as said pickup element moves toward and into engagement with successive workstock sheets.
 10. The invention as set forth in claim 9 wherein said stop means comprises resilient finger means extending from said second member and rotatable therewith and oriented with respect to said pickup element to resist rotation of said second member as said pickup element moves into engagement with successive workstock sheets.
 11. In apparatus for feeding successive sheets of workstock, means for supplying successive sheets of workstock, a delivery assembly for conveying successive sheets of workstock to an associated machine or other operative destination, a transfer mechanism for individually transferring successive workstock sheets from said storage assembly to said delivery assembly, said transfer mechanism including rotatable shaft means and at least one vacuum pickup element mounted on said shaft means for rotation about an axis extending transversely of the path of movement of the workstock sheets and being movable between first and second positions, valve means selectively communicating a vacuum source to said element as the same travels between said positions and means carried on and rotatable with said shaft means for varying the rate of rotational movement of said vacuum pickup element in response to said element being in one of said first and second positions.
 12. The invention as set forth in claim 11 wherein said transfer mechanism comprises first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member.
 13. The invention as set forth in claim 12 which includes means for storing a stack of workstock sheets and for elevating the same in a manner such that the uppermost sheet of said stack thereof is disposed in a preseLected orientation with respect to said transfer mechanism.
 14. The invention as set forth in claim 13 wherein said elevating means is actuatable in response to movement of one of said members.
 15. The invention as set forth in claim 13 which includes level sensing means for ascertaining the vertical height of the uppermost sheet of said stack thereof on said storage means.
 16. The invention as set forth in claim 15 which includes clutch means drivingly connecting said elevating means with one of said first mentioned members, and wherein said leveling sensing means includes means engageable with the stack of workstock sheets for controlling actuation of said clutch means.
 17. In an apparatus for feeding successive sheets of workstock, means for supplying successive sheets of workstock, a delivery assembly for conveying successive sheets of workstock to an associated machine or other operative destination, a transfer mechanism for individually transferring successive workstock sheets from said storage assembly to said delivery assembly, said transfer mechanism comprising at least one vacuum pickup element, first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member and being movable between first and second positions, valve means selectively communicating a vacuum source to said element as the same travels between said positions and stop means for yieldably resisting rotational movement of said second member as said pickup element moves toward successive workstock sheets.
 18. The invention as set forth in claim 17 wherein said stop means comprises resilient finger means extending from said second member and rotatable therewith and oriented with respect to said pickup element to resist rotation of said second member as said pickup element moves toward successive workstock sheets.
 19. The invention as set forth in claim 18 which includes clutch means for drivingly connecting said second member with a source of motive power when said finger means stops rotation of said pickup element mounted on said second member.
 20. The invention as set forth in claim 18 which includes clutch means for preventing reverse rotation of said second member upon engagement of said finger means with an associated stop member.
 21. In an apparatus for feeding sheet workstock, at least one pickup element adapted for releasable engagement with successive workstock sheets; means for operatively supporting said pickup element including a transfer member movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination; means for gradually stopping movement of said transfer member in said first position in order to absorb the momentum of movement thereof; and means for moving said transfer member and said pickup element supported thereon along a preselected path.
 22. The invention as set forth in claim 21 wherein said compound movement of said transfer member and said pickup element supported thereon is defined by pivotal and rotational movement of said transfer member about parallel axes extending substantially transversely of the direction of movement of the workstock sheets.
 23. The invention as set forth in claim 21 wherein said operatively supporting means further includes a first member extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first member and said transfer member.
 24. The invention as set forth in claim 23 wherein said transfer member is rotatable relative to said first member.
 25. The invention as set forth in claim 23 wherein said transfer member is pivotable about a transverse axis extending parallel of said first member.
 26. The invention As set forth in claim 25 which includes a plurality of vacuum operated pickup elements, and means on said transfer member defining a plurality of vacuum passages corresponding one to each of said elements.
 27. The invention as set forth in claim 26 which includes valve means selectively opening and closing a circuit between a vacuum source and said passage means, said valve means thereby automatically communicating said vacuum source with the particular pickup element disposed closest to the sheet workstock when said transfer member is disposed in said first position, while blocking communication between said vacuum source and those pickup elements which are spaced away from the sheet workstock.
 28. The invention as set forth in claim 21 wherein said means for gradually stopping movement includes finger means supported by said transfer member, and interferring means for engaging said finger means in said first position of said transfer member.
 29. The invention as set forth in claim 28, wherein said interferring means is a shaft extending transversely of the path of the workstock sheets.
 30. The invention as set forth in claim 28 wherein said finger means comprises a sleeve connected to said transfer member and at least one radially extending finger member having one end connected to said sleeve.
 31. The invention as set forth in claim 30 wherein said finger member is fabricated from a resilient material 30, provide a shock absorbing function upon contact of said finger with said shaft.
 32. In an apparatus for feeding sheet workstock, at least one pickup element adapted for releasable engagement with successive workstock sheets; means for operatively supporting said pickup element including a transfer member movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination; means for moving said transfer member and said pickup element supported thereon along a compound curved path, said compound curved path of said transfer member and said pickup element supported thereon being defined by pivotal and rotational movement of said transfer member about parallel axes extending substantially transversely of the direction of movement of the workstock sheets; and which includes stop means for resisting rotational movement of said transfer member as said pickup element moves toward and into engagement with successive workstock sheets.
 33. The invention as set forth in claim 32 which includes elevating means actuatable in response to movement of said transfer member for raising a stack of workstock sheets toward said pickup elements.
 34. The invention as set forth in claim 29 wherein said stop means yieldably resists rotational movement of said transfer member as said pickup element moves toward engagement with successive workstock sheets, said stop means comprising a stop member, resilient finger means extending from said transfer member and rotatable therewith and oriented with respect to said pickup elements and engageable with said stop member to preclude rotation of said transfer member as said pickup elements move into engagement with successive workstock sheets, and wherein said means for moving said transfer member includes clutch means for drivingly connecting said transfer member with a source of motive power when said finger means stops rotation of said pickup element, and prevents reverse rotation of said transfer member upon engagement of said finger means with said stop member.
 35. In an apparatus for feeding sheet workstock, at least one rotatable pickup element having at least two nozzles, each nozzle being adapted for releasable engagement with successive workstock sheets, means for operatively supporting said pickup element including rotatable shaft means movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wheRein said pickup element is adapted to deliver the workstock sheet to a predetermined destination, said shaft means defining a number of longitudinally interiorly extending passages conforming to the number of said nozzles, each passage being in communication with one of said nozzles; and valve means for individually communicating a vacuum source to one of said passages while blocking said source from the remainder of said passages.
 36. The invention as set forth in claim 35, wherein said valve means is comprised of a tubular sleeve having a radially extending aperture and rotatably supported by said shaft means, and wherein said shaft means includes a number of transversely extending passages, each passage being in communication with one of said longitudinally extending passages.
 37. The invention as set forth in claim 36, wherein said radially extending aperture is in communication with a source of vacuum and wherein said source is communicable to one of said transversely extending passages via said aperture by relative rotation between said shaft means and said sleeve.
 38. The invention as set forth in claim 37, further including a rotary union for connecting said valve means with the vacuum source.
 39. The invention as set forth in claim 35 wherein said pickup element includes at least two transversely extending bores relative to said shaft means, each of said bores being in communication with one of said longitudinally extending passages.
 40. The invention as set forth in claim 39, wherein each of said nozzles is comprised of a first tubular section adapted to be removably inserted in one said bores, a second tubular section adapted to engage a workstock sheet, and a third tubular section slidably interposed between said first and second tubular sections.
 41. The invention as set forth in claim 40 further including a spring member located in said tubular section to bias said second tubular section relative to said workstock sheet.
 42. The invention as set forth in claim 39, wherein each of said bores may be selectively plugged.
 43. The invention as set forth in claim 35, including a plurality of pickup elements operatively supported by said shaft means, and wherein some of said pickup elements are selectively plugged.
 44. In an apparatus for feeding sheet workstock, at least one rotatable pickup element adapted for releasable engagement with successive workstock sheets, means for operatively supporting said pickup element including a transfer mechanism movable between a first position wherein said pickup element is adapted to engage a workstock sheet and a second position wherein said pickup element is adapted to deliver the workstock sheet to a predetermined destination, said mechanism including relatively rotatable means adapted for selective engagement with relatively nonrotatable means for interrupting rotation of said pickup element at said first position, and means for storing a stack of workstock sheets and for moving the same in response to movement of said transfer mechanism whereby preselected sheets of said stock are disposed in a preselected orientation with respect to said pickup element.
 45. The invention as set forth in claim 44, wherein said transfer mechanism comprises first and second members extending transversely of the path of the workstock sheets, and means extending between and operatively connecting said first and second members, with said pickup element being operatively mounted on said second member.
 46. The invention as set forth in claim 45, wherein said second member is rotatable relative to said first member and wherein said second member is pivotable about a transverse axis extending parallel of said first member.
 47. The invention as set forth in claim 46, which includes a plurality of vacuum operated pickup elements, and means on said second member defining a plurality of vacuum passages corresponding one to each of said elements.
 48. The invention as set forth in claim 45, further including cam meaNs for operatively oscillating said second member between said first and second positions, and first linkage means for operatively connecting said cam means to said means extending between and operatively connecting said first and second member.
 49. The invention as set forth in claim 48, further including sheet level sensing means for sensing the level of the workstock sheets relative to said first position of said pickup element.
 50. The invention as set forth in claim 49, further including second linkage means for operatively connecting said sheet level sensing means to said cam means.
 51. The invention as set forth in claim 46 wherein said cam means is a rotatable disc having a flat, and wherein said second linkage means includes a rotatable arm having one end displaceable about the outer periphery of said rotatable disc.
 52. The invention as set forth in claim 51 wherein said first linkage means includes an arm having one end eccentrically connected to said rotatable disc and an opposite end connected to said operatively connecting means.
 53. The invention as set forth in claim 51 wherein said operatively connecting means includes a bellcrank having one end rotatably connected to said second member and having an intermediary portion connected to said first member.
 54. The invention as set forth in claim 53, further including cam means for effecting movement of an opposite end of said bellcrank. 